Intent选择器，开系统图库选择图片，开相机拍照

 //开启系统图库        Intent intent1 = new Intent(Intent.ACTION_PICK);        intent1.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");        //开相机        Intent intent2 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);        File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), System.currentTimeMillis() + ".jpg");        path = file.getAbsolutePath();        Uri path = Uri.fromFile(file);        intent2.putExtra(MediaStore.EXTRA_OUTPUT, path);        //intent选择器        Intent chooser = Intent.createChooser(intent1, "选择头像");        chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[]{intent2});        startActivityForResult(chooser, 100);

@Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        if (resultCode == RESULT_OK && requestCode == 101) {            String filePath = "";            if (data != null) {                //图库选图                //对于部分手机来说，在安卓原生的拍照程序基础上做了修改                //导致拍照的照片会随着arg2返回到这里                Uri uri = data.getData();                if (uri != null) {                    if (!uri.getPath().equals(imageUri.getPath())) {                        //图库                        Cursor cursor = getContentResolver().query(uri, new String[]{MediaStore.Images.Media.DATA}, null, null, null);                        cursor.moveToNext();                        filePath = cursor.getString(0);                        cursor.close();                    } else {                        //拍照                        //拍照的路径依然是cameraPath                        filePath = cameraPath;                    }                } else {                    Bundle bundle = data.getExtras();                    //bitmap是拍照回来的照片                    Bitmap bitmap = (Bitmap) bundle.get("data");                    //TODO 将bitmap存储到SD卡                }            } else {                //相机拍照                filePath = cameraPath;            }        }        super.onActivityResult(requestCode, resultCode, data);    }

调用系统的摄像头进行拍照：

第一步：声明个imageUri，以便拍照时返回用

第二步：

 //创建file对象，用于存储拍照后的图片                File outputImage = new File(getExternalCacheDir(), "output_image.jpg");                try {                    if (outputImage.exists()) {                        outputImage.delete();                    }                    outputImage.createNewFile();                } catch (IOException e) {                    e.printStackTrace();                }                if (Build.VERSION.SDK_INT >= 24) {                    //android 7.0后的特性，直接使用fromFile不安全，所以用getUriForFile                    imageUri = FileProvider.getUriForFile(MainActivity.this, "com.example.fileprovider", outputImage);                } else {                    imageUri = Uri.fromFile(outputImage);                }                //启动拍照相机程序                Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);                startActivityForResult(intent, TAKE_PHOTO);

第三部：

   @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        switch (requestCode) {            case TAKE_PHOTO:                if (resultCode == RESULT_OK) {                    try {                        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));                        imageView.setImageBitmap(bitmap);                    } catch (FileNotFoundException e) {                        e.printStackTrace();                    }                }                break;        }    }

第四部：

因为用到了FileProvider，所以需要在manifest中注册

 <provider            android:name="android.support.v4.content.FileProvider"            android:authorities="com.example.fileprovider"            android:exported="false"            android:grantUriPermissions="true">            <meta-data                android:name="android.support.FILE_PROVIDER_PATHS"                android:resource="@xml/file_path" />        </provider>

同时也要为了兼顾旧版本，需要加权限。

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

第五部：创建xml文件夹，并创建file_path文件

<?xml version="1.0" encoding="utf-8"?><paths xmlns:android="http://schemas.android.com/apk/res/android">    <external-path        name="my_images"        path="" /></paths>

调用系统图库选择图片

  if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)                        != PackageManager.PERMISSION_GRANTED) {                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 100);                } else {                    openAlbum();                }

  private void openAlbum() {        Intent intent = new Intent("android.intent.action.GET_CONTENT");        intent.setType("image/*");        startActivityForResult(intent, CHOOSE_PHOTO);    }

 @Override    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {        if (requestCode == 100) {            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {                openAlbum();            } else {                Log.i("TAG", "onRequestPermissionsResult: " + "error");            }        }    }

然后在OnActivityResult里面

case CHOOSE_PHOTO:                if (resultCode == RESULT_OK) {                    if (Build.VERSION.SDK_INT >= 19) {                        handlerImageOnKitKat(data);                    } else {                        handlerImageBeforeKitKat(data);                    }                }                break;

private void handlerImageOnKitKat(Intent data) {        String imagePath = null;        Uri uri = data.getData();        if (DocumentsContract.isDocumentUri(this, uri)) {            //如果是document类型的uri            String docId = DocumentsContract.getDocumentId(uri);            if ("com.android.providers.media.documents".equals(uri.getAuthority())) {                String id = docId.split(":")[1];                String selection = MediaStore.Images.Media._ID + "=" + id;                imagePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);            } else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {                Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));                imagePath = getImagePath(contentUri, null);            }        } else if ("content".equalsIgnoreCase(uri.getScheme())) {            //content类型            imagePath = getImagePath(uri, null);        } else if ("file".equalsIgnoreCase(uri.getScheme())) {            //file类型            imagePath = uri.getPath();        }        displayImage(imagePath);    }    private void handlerImageBeforeKitKat(Intent data) {        String path = getImagePath(data.getData(), null);        displayImage(path);    }    private void displayImage(String path) {        if (path != null) {            Bitmap bitmap = BitmapFactory.decodeFile(path);            imageView.setImageBitmap(bitmap);        }    }    private String getImagePath(Uri data, String selection) {        String path = null;        Cursor cursor = getContentResolver().query(data, null, selection, null, null);        if (cursor != null) {            if (cursor.moveToFirst()) {                path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));            }            cursor.close();        }        return path;    }